1940's Vintage Black Onyx Cameo Screw-On Earring.

1940's Vintage Black Onyx Cameo Screw-On Earring. I am not an expert on Jewerly. Looks like the real deal to me.. No Distinguishing identifying markings to go by.. I am going by the look & tarnishing plus screw back. I re-surcharged them online and this is what I came up with.. The quarter doesn’t come with it! I only used the quarter for size comparison.